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Talk:Planetary Information/@comment-174.4.146.189-20140921215058
May I make a few observations? The planet is dominated in the northern hemisphere by a single, large landmass, and while there are seas in the southern hemisphere, there are few water bodies which will demonstrate typical circulation patterns. Let me begin at the center of the map. This large body of water is almost completely in the southern hemisphere, so its circulation will be counter-clockwise, with warm, equatorial waters moving southward on the western margin, and cold, polar waters moving northward on the eastern margin. Where this current changes direction (e.g. where it moves from south to east, or from east to north), nutrient-rich water from below will be drawn upwards in the water column, with the consequence that surface waters in these areas will be particularly productive. At the eastern margin of this small ocean, the current will diverge, with some water heading north while the rest continues eastward around the pole. In the western hemisphere, some of this eastward current will diverge again, heading northward into a small sea. The circulation in this sea will also be counter-clockwise, with some warmer waters escaping westward to join the main ocean gyre in the eastern hemisphere. The forces which cause circulation in the southern oceans will not have similar effects on the interior seas of the northern hemisphere, as most of these do not connect with other seas or oceans. The more important cycle in the northern hemisphere will be seasonal. If this planet is earth-like, it's very likely that the lack of circulation in northern hemisphere water bodies will allow those most northerly to completely freeze over every winter (see the Great Lakes). This cycle will have great influence culturally, as folks who get fish from the water will need at least two modes of doing so, or will have to adapt to long periods when fishing is either too dangerous (e.g. spring break up), or simply impossible (e.g. ice may be 3m thick in places). The presence of ice on the surface will also have significant impact on transportation; any water-going vessels will be useless when the seas are frozen solid. Predictably, then, cultures located here will likely develop year-round transport methods that use the flat coastal zone to connect with other places. The interior regions of this large continent will also be very dry. There isn't much water in the atmosphere of the northern hemisphere, and quite a few mountain ranges, so the leeward areas will be dry (no trees maybe), and if these are also extensive, they may become deserts. This will be especially evident at the northern and southern edges of the inter-tropical convergence zone (ITCZ), where dry, descending air not only prevents rainfall from developing, but the local high pressure sets up the trade winds (blowing NE-SW in the north; SE-NW in the south). In the southern hemisphere, most of this zone is over the ocean and blows to the northwest, toward the equator. The map shows quite a few islands in the southern ITCZ, and these will be humid--likely covered with jungle--as they receive all the moisture of the trade winds blowing in off the ocean. The northern perimeter of the main southern ocean will also be humid and densely vegetated, with many streams and rivers. These river basins will receive fairly constant precipitation; vegetation should smooth out peak flows, but there may be local flooding on occasion. However, the general lack of water in the northern hemisphere will mean there are fewer rivers and streams, less vegetation, and wider fluctuations in seasonal weather. The dominant weather feature of the northern hemisphere will be wind, which may change direction seasonally, but will likely never stop blowing for very long. As settlements will likely concentrate in lower areas (e.g. closer to water), these will also likely be found in valleys or on the continental margins, where wind velocities will be even higher. As the ground here is relatively dry, winds in the north will also carry a lot of sand. This will influence architectural forms and personal dress habits, among other cultural features. Without water, transport in the north will likely be overland by foot or other conveyance; in the south, cultures will probably take advantage of the ocean to get around. It's a start.